The long-term goal of the K08 Mentored Research Clinical Scientist Development Award is to expand the applicant's research capabilities to include adolescent Reservation-dwelling American Indian (RDAIs) substance use. The proposed training and research plan fit well with NIDA's strategic plan to promote research on health disparities related to substance use and to increase minority representation in substance use research. The candidate is an American Indian, and her prior research experiences have been in the area of health disparities related to alcohol use in adult RDAIs, involving quantitative methodologies. Although research shows that RDAI adolescents are at a higher risk for substance use, we know little about the reasons for this increased risk. In a group of adult RDAIs, we found that RDAIs as a group expected less of a drop in access to some basic reinforcers (access to housing, employment, etc) as a function of heavy drinking compared to middle class Caucasians. Because adults typically begin using alcohol and other drugs during adolescence, studying reinforcers for not using in adolescent RDAIs is a high public health priority. The present application proposes a structured program of mentoring, training, and supervised research to increase the candidate's capacity to conduct high-quality research blending state of the art qualitative and quantitative methodologies. This K08 will accomplish these objectives through the career development and research plans. The career development plan consists of mentored training in measurement development, adolescent development as it relates to substance use, adolescent American Indian substance use research, qualitative and advanced quantitative methods, and training in translating research findings to treatment and prevention development. The Brown University Center for Alcohol and Addiction Studies provides an intellectually stimulating environment with outstanding resources to ensure the successful achievement of the candidate's training plan. The candidate has assembled a team of mentors who are each experts and nationally known for their research in areas specific to the training plan. Dr. Christopher Kahler (primary mentor) is an expert in measurement development, advanced quantitative methods, and translational research. Dr. Don Operario (co- mentor) is an expert in community based participatory research focusing on health disparities in ethnically diverse populations, and in the use and implementation of mixed qualitative and quantitative methods. Dr. Kristina Jackson (co-mentor) is an expert in adolescent development and substance use involvement. Finally, Dr. Paul Spicer (co-mentor) is an expert in American Indian research with adults and adolescents. The research plan proposes a three phase plan to test a theory of risk for substance use in adolescent RDAIs. The first phase employs qualitative methods to identify and construct a typology of factors unique to this population - i.e., the social/environmental, cultural, and developmental context - that might reinforce observed patterns of substance use. Based on these interviews, we will develop a measure of these reinforcers to be used in Phase 2. Phase 2 is a psychometric evaluation of the measure that will be developed from the qualitative interviews and focus groups conducted in Phase 1. Phase 3 is a cross-sectional test of the association between these factors and substance use involvement. The candidate will write an R01 in order to follow these individuals to investigate the role of these factors longitudinally. Results of this program of research are expected to ultimately inform the development of a theoretically based, developmentally and culturally appropriate theory to prevent the use and harms associated with substance use in this population. It is anticipated that this prevention intervention model will target important determinants of substance use, which will be characterized in this proposed K-Award and subsequent R01 submission. In sum, this award will provide the candidate the necessary expertise to develop an independent innovative research program that will generate findings that will contribute to our understanding of risk for substance use in this high risk RDAI group and inform more effective prevention and intervention programs.